The HHR has electric assist steering, instead of a mechanical pump. Electric power steering is a system where the power steering pump is driven by an electric motor instead of a belt from the crankshaft.
If the correct jump start proceedure is not followed exactly, you will blow the power steering fuse when the jumper cables are connected.
Check in the underhood relay box , Fuse #1, a 60 amp fuse for the electronic power steering control module. Maybe you blew this fuse. Replace the fuse with one that is the exact same amperage rating.